The present invention relates to a locking filler cap mechanism that is particularly adapted for use on automobiles to prevent unauthorized access to the fuel tank of an automobile.
With the ever increasing cost of fuel, it is becoming increasingly desirable to equip an automobile with means for preventing unauthorized access to the fuel tank of the automobile. However, it is equally desirable that the means provided do not present a significant inconvenience to the owner of the vehicle.
It is the principle object of the present invention, therefore, to provide an improved fuel cap locking mechanism which functions reliably and yet is relatively simple and inexpensive to manufacture and convenient to use.
In general, the filler cap in the present invention is provided with an annular ring of ratchet teeth formed on the underside of the cap. Mounted to the filler neck adjacent the opening is a housing containing an electrical solenoid having a spring-loaded armature pin. The armature pin is mechanically coupled to a locking pawl which projects outwardly from the housing and engages the ratchet teeth in the bottom of the filler cap when the cap is fastened over the filler neck opening. Pivotally connected to the locking pawl is a lock-out pin which when pivoted into alignment with the locking pawl, projects outwardly from the housing approximately the same distance as the locking pawl.
When the filler cap is installed on the end of the filler neck and the pawl is engaged with the ratchet teeth of the cap, the lock-out pin is non-aligned with the pawl. However, when the solenoid is activated, preferably by a remotely located switch in the dashboard area of the vehicle, the armature pin is drawn into the solenoid, thereby retracting the pawl and disengaging it from the ratchet teeth in the filler cap. Simultaneously as the armature pin and pawl are retracted, the lock-out pin is rotated into alignment with the pawl by virtue of a cam surface formed in the housing wall. When the solenoid is de-energized after momentary activation of the remote switch, the spring-loaded armature pin urges the pawl and lock-out pin assembly outwardly from the housing. However, the pawl is prevented from re-engaging the ratchet teeth in the filler cap by virtue of the lock-out pin which, now aligned with the pawl, contacts the bottom surface of the filler cap and impedes further return movement of the pawl. Consequently, the filler cap can now be removed. In addition, when the filler cap is re-installed onto the filler neck after removal, the rotation of the filler cap causes the lock-out pin to be pivoted into its non-aligned position when contacted by the bottom surface of the filler cap, thereby permitting the pawl to automatically re-engage the ratchet teeth in the filler cap. Thus, it will be appreciated that with the locking arrangement of the present invention, the filler cap can be removed upon a single momentary activation of a remotely located switch and also, upon subsequent re-installation of the filler cap, is automatically locked to prevent unauthorized removal of the filler cap.